Tetrahedron Letters No. 41, Pp 3967 - 3970. Opergamon Press Ltd. 1978. Printed in Great Britain.

0040-4039/78/100%-3967jd02.00/0

NEW REAGENT FOR CONVERSION OF OLEFINS TO S-HYDROKYSELEMDES

D. Labar, A. Krief and L. Hevesi

Facult6s Universitaires Notre-Dame de la Paix Department of Chemistry 61, rue de Bruxelles, B-5000 - Namur (Belgium)

Thermal elimination of selenoxides has been documented recently as a highly potent mean

of producing olefins I-6a

,allylalcohols 5,6b-10

and a,S-unsaturated carbonyl compounds 1,2,11,12

The by-product in these reactions is aryl (or alkyl) selenenic acid, a species which was descri-

bed l-3911 to disproportonate rapidly to the corresponding diselenide and seleninic acid.

It occured to us that the reverse reaction, i.e. addition of selenenic acids 13

to olefins,

would also be a very useful process, since it would allow the generation of a number of func-

tionalities from olefins.

We present here our first efforts directed tom& this goal. The key step of the reaction

described on Scheme I,arises from the observation that unstable phenyl and methyl selenenic acid

or alike can be formed 14

from readily available and easily handled phenyl 15d

and methyl 15b

seleninic acids and aqueous hypophosphorus acid (50%) at room temperature.

These intermediates are trapped in situ by a variety of olefinic products,when the reaction

is carried out in THE' solution,leading to the corresponding S-hydroxyselenides 5inhigh to good -

yield (RSe02H,l:5 eq.; H3P02, 2.25 eq.; olefin, leq./THF)16. Interestingly, the whole process

occurs in a relatively mild reducing and neutral medium.

Scheme I

RSe02H + H PO w "RSeOH" ------w RI uR2

3 2

R4

1 2 3 4 5a 5b - - - - -

3967

3968 No. 41

Entry I R1 R2 R3 R4 ,

a '8*17

b 'gH17

c C5H11

d C5H11

e 'gH17

f 'gH17

g 'gH17 h

'8*17 i

cH3

j CH3

H

H

CH3

H

'SH17 H

'SH17 H

H

H

H H

H H

H H

H CH3

H H

H 'SH17

H H

H 'SH17

CH3 (CH ) -CHC2H

221

CH3

CH3 (CH ) -CHC2H

2 21 CH3 _-~~--~_--~---_-~~-~~_ _-----_L____________

R each regioisomer was separated by TLC Si02

RX a mixture of regioisomersis obtained

(+) starting olefin is also recovered (40%)

R

'6*5

76 38/38*

91 62129

78 **

76 **

63 -

38(+) -

82 -

74 -

80 80100

86 86100

I .--_------_--_---_--

hr.

2.5

1.5

3.5

3

4.5

4.5

3

1.5

From our experimental results the following observations can be made :

I. Phenyl selenenic acid seems to react much faster than methyl selenenic acid.

2. Mono and trisubstituted olefins react quite rapidly whereas in the disubstituted cases the

rate of the reaction is highly dependant on the length of the chain and the stereochemistry

of the starting olefin - the Z isomer reacting faster than the E.

3. The reaction is highly regioselective in the case of trisubstituted olefins, the selenyl moi-

ety being held by the less substituted carbon atom (no trace of the other isomer was detected

by N.M.R.). However, a mixture of regioisomers is observed in the case of terminal olefins

and their ratio is dependant on the nature of the selenenic acidand probably also on the ex-

perimental conditions used.

4. In the case of disubstituted olefins we have investigated the stereochemistry of the addition

and found that the reaction is highly bistereoselective (>95%) and occured by trans addition

of the hydroxyl and the selenyl moieties (by comparison with authentic samples of 5e and 5f - -

obtained 17 stereoselectively (100%) respectively from Z and E 8-9 oxidooctadecene and potas-

sium methyl selenolate).

f3-hydroxyselenides are valuable intermediates in organic synthesis. They can be selectively

transformed to epoxides 18,19 a-bromohydrins

20 7 ally1 alcohols

5,6b-10

compounds 1,2,11,12

a-selenocarbonyl compounds ;1,22

a,B-unsaturated carbonyl 21 9 , alcohols and LIefins 17.

3970 No. 41

References

1. D.L.J. Clive, Tetrahedron Report 50, Tetrahedron, 2, 1049 (1978)

2. K.B. Sharpless, K.M. Gordon, R. . Lauer, D.W. Patrick, S.P. Singer, M.W. Young, Chemica

Scripta, z, 9 (1975)

3. K.B. Sharpless, M.W. Young and R.F. Lauer, Tet. Lett., 1979 (1973)

4.

5.

6.

7.

8.

9.

10.

II.

12.

D.L.J. Clive, J.C.S. Chem. Comm., 695 (1973)

H.J. Reich and S.K. Shah, J. Amer. Chem. Sot., 97, 3250 (1975)

a) D. Labar, W. Dumont, L. Hevesi and A. Krief, Tet. Lett., 1141 b) D. Labar, W. Dumont, L. Hevesi and A. Krief, Tet. Lett., 1145

a) K.B. Sharpless and R.F. Lauer, J. Amer. Chem. Sot., 95, 2697 b) K.B. Sharpless and R.F. Lauer, J. Org. Chem., 2,.429 (1974)

H.J. Reich, J. Org. Chem., 2, 428 (1974)

D. Seebach and A.K. Beck, Angew. Chem. Int. Ed., 12, 806 (1974)

W. Dumont, P. Bayet and A. Krief, Angew. Chem. Int. Ed., 13, 804

H.J. Reich, I.L. Reich and J.M. Renga, J. Amer. Chem. Sot., 97,

J.N. Denis, W. Dumont and A. Krief, Tet. Lett., 453 (1976)

(1978)

(1978)

1973)

(1974

434 (

1 1975)

13. H. Rheinboldt and E. Giesbrecht, Chem. Ber., E, 1974 (1955), reported the isolation of p-Nitrophenylselenenic acid by reacting p-Nitrophenylseleninic acid and 1.5 eq. of hypo- phosphorus acid butwerenot able to isolate the phenylselenenic acid.

14. Analogous - but not regioselective in case of trisubstituted olefins - reactions using benzeneselenenyl trifluoroacetate 8 or benzeneselenenyl bromide 7b have been already des- cribed

15. a) Prepared from diphenyl diselenide and H202 (6 eq.) in dioxane at O"C, mp 120-121". D. De Filippo and F. Momicchioli, Tetrahedron, 2, 5733 (1969)

b) Methyl seleninic acid, mp 122', already described in 1856 (F. Wohler and J. Dean, Annalen, 97, 1 (1856)). was prepared as for phenylseleninic acid 15a

16. To a mixture of seleninic acid (1.5 IO-3 mole) and olefin (1.0 IO-3 mole) in THF is added 50% aqueous hypophosphorous acid solution (2.25 IO-3 mole). After completion of the reac- tion (monitored by TLC Si02 Merck, I:9 Ether/pentane) usual work up and PLC purification of crude products give the 8-hydroxyselenide in the yields described in the text.

17. J. Remion and A. Krief, Tet. Lett., 3743 (1976); comparison of their NMR spectra and by VPC analysis

18. W. Dumont and A. Krief, Angew. Chem. Int. Ed., 16, 350 (1975)

19. D. Van Ende, W. Dumont and A. Krief, Angew. Chem. Int. Ed., 3, 700 (1975)

20. M. Sevrin, W. Dumont, L. Hevesi and A. Krief, Tet. Lett., 2647 (1976)

21. Already disclosed by A. Krief a) At the fifth International Symposium : Synthesis in Organic Chemistry, held at Oxford,

July 26, 1977 by the Chemical Society b) At the symposium on Silicon and Selenium in Organic Chemistry during the M.A.R.M. meeting

held in Baltimore, April 6, 1978 by the American Chemical Society

22. J. Lucchetti and A. Krief, submitted to publication

23. L. Hevesi, J.B.Nagy, A. Krief and E.G.Derouane,Org. Magn. Res., ,, 14 (1977)

24. T. Hori and K.B. Sharpless, J. Org. Chem., 43 1689 (1978) - 25. H.J. Reich, S. Wollowitz, J.E. Trend, F. Chow and D.F. Wendelborn, J. Org. Chem., 2,

1697 (1978)

(Received in1JI( 2 August 1978; accepted for Publication 11 August 1978)